take a potshot at
take a pot shot
1. To fire a shot easily or recklessly. The phrase comes from hunting (in which shots ideally yield food for one's pot). You boys can't just take pot shots at any creature you see—there are rules we have to follow out here!
2. By extension, to direct a cheap, unfair, or opportunistic insult or criticism at someone, especially someone who is vulnerable. Now that everyone knows I was involved in that scandal, the reporters love taking pot shots at me.
take a potshot at someone or something
1. Lit. to shoot at someone or something, as with a shotgun. (A potshot refers to the type of shooting done to provide meat for the cooking pot.) The hunters were taking potshots at each other in the woods. Someone has been taking potshots at my mailbox!
2. Fig. to criticize or censure someone or something, often just to be mean. Why are you taking potshots at me? What did I do to you? Everyone in the audience was taking potshots at the comedian's toupee.